Coated food container



Patented Oct. 13, 1953 UNITED STATES PATENT OFFICE COATED FOOD CONTAINERAlbert C. Edgar, Palos Heights, 11]., asslgnor to Wilson & Co.,Inc., acorporation of Delaware Nb Drawing. Application April 9, 1947, SerialNo. 740,487

sealed cans are then placed in a steam retort or similar cooker, andcooked, frequently under pressure, for about one to two hours, theamount of pressure and the time of cooking. depending on the kind ofmeat and the size of can used.

A serious problem in the manufacture of canned meats has been thetendency of these products to adhere to the interior surfaces of thecans. This adhesion of meat tothe can not only causes diificulty inefiectinga complete removal of the contents of the can, but also resultsin wastage and inconvenience to the consumer who has to scrape off theadheringmeat from the sides and bottom of the container. Furthermore,the appearance of the contents is frequently impaired, particularly withproducts such as luncheon meats which are removed from the can as arigid cohesive unit, because portions of the adhering surface meat aretorn away during removal of the meat from the can.

This tendency of the meat to adhere to the partially successful and farfrom satisfactoryu The application of a film of gelatin to the insidesurfaces of meat cans has also been practiced in the endeavor to preventadhesion of meat to the sides of the cans, but without real success.

Another means used in the industry in comhating this problem is toencase the meat in paper, such as parchment and like papers, beforeplacing the paper-covered meat inthe can. Such a treatment is alsounsatisfactory because, while there is no adhesion of meat to the wallsand bottom of the can, there is considerable adhesion of meat to thepaper.

I have discovered that I can eliminate adhesion between the interiorsurfaces of a can and the surfaces of meat contained therein, byapplying to the interior surfaces of the can, a thin film of anon-hydroxy material selected from the group consisting of polyhydroxyalcohol partial esters of those higher saturated and unsaturated innerethersof hexahydroxy alcohol partial esters of those higher saturatedand unsaturated fatty acids containing at least 12 carbon atoms, andmixtures thereof. Examples of such materials are glycerol mono-oleate,glycerol monostearate, mannitol mono-oleate, mannitol monostearate,sorbitol mono-oleate, sorbitol monopalmitate, mannitan mono-oleate,mannitan mono-stearate, sorbitan mono-palmitate and sorbitanmono-stearate.

My invention will be readily understood from the following specificexamples. These examples, it will be understood, are illustrative only,and are not to be construed as limiting my invention.

Example 1 Thirty twelve-ounce oblong cans with tincoated interiorsurfaces, of the type used in canning luncheon meats, were divided intothree equal groups and marked I, J and K.

The cans in lot I were treated by spraying 0.1 ram of melted glycerolmono-stearate uniformly over the inner surfaces of each can.

The cans in lot J were treated by spraying 0.1 gram of melted mannitanmono-stearate uniformly over the inner surface of each can.

The cans in lot K were treated by spraying about 0.6 gram of melted larduniformly over the inner surfaces of each can.

All three lots were then filled with beef luncheon meat, sealed andcooked in a steam retort under ten pounds steam pressure for ninetyminutes. After removal from the steam retort the cans were stored forseven days at 70 F. and

then opened.

The contents of lots I and J were easily removed by inverting the can,whereupon the meat slid out. There was no adhesion of meat particles tothe inner surfaces of the cans.

In the case of lot K, however, the meat adhered so tenaciously to theinner surfaces of the can that vigorous shaking was necessary to removethe contents of the cans. Even this procedure failed to remove thecontents of {our cans, and it was necessary to use a fork to dig out thea meat.

.60 fatty acids containing at least lzcarbonatoms,

Example 2 Thirty twelve-ounce oblong cans with tincoated interiorsurfaces, of the type used in canning luncheon meats, were divided intothree equal groups and marked L, M and N.

The cans in lot Lwere treated by swabbing the inner surfaces withglycerol mono-oleate.

The cans in lot M were treated by swabbing the inner surfaces withmannitan mono-oleate.

The cans in lot N were treated by swabbing the inner surfaces withmelted lard.

The swabbing, in all instances, was done by hand with a cotton swabdipped in the liquid coating material. Approximately 0.3 gram of thecoating material per can was applied in this manner.

All of the cans were then filled with pork luncheon meat, sealed andcooked as in Example 1. After removal from the steam retort, the canswere stored at 70 F. for 14 days and then opened. The contents wereremoved by shaking the inverted cans. Examination of the inner surfacesof the containers showed that while there was some adhesion of meatparticles to the surfaces of the cans in lot L and lot M, the adhesionof meat particles to the cans in lot N was objectionably greater.

While I prefer to useabout 0.2 gram of coating material per about 45-50square inches of surface, lesser amounts than this will prove beneficialin minimizing adhesion of meat to the said surfaces. 1 have found thatglycerol monostearate and mannitan mono-stearate are ex tremelyeffective for this purpose, even when only 0.1 gram of these materialsis used per about 45-50 square inches of surface. These materials areparticularly effective in preventing adhesion of beef-containing meatproducts to the insides of the cans. Beef-containing meat productsadhere to the inner surfaces of the cans even more tenaciously than doother types of meat products. Lard coated cans are practically withouteifect in minimizing adhesion of these beef-containing products.Glycerol mono-stearate and mannitan mono-stearate were far superior tolard in this respect, and cans interiorly coated wtih these materialsresult in a complete elimination of adhesion between the meat and insiesurfaces of the cans. 7

It is manifest, from the above examples, that the coating materials ofthe present invention can be applied to the interior surfaces of thecans in any of several ways, as desired: My invention is not to beconstrued as limited to the methods of application described in theillustrative examples since other methods may be used, as will beevident to skilled workers in the art. Nor is it intended that it belimited in its application to animal protein matter, since it is readilyapplicable to marine protein materials, such as fish and fish productsas well. Nor is my invention to be construed as limited to the coatingof cans or similar containers since paper or similar wrapping materialscan be covered with the coating materials of the present invention andthe treated paper wrapped around meats prior to being placed in thecans. Furthermore, my invention is applicable to plastic and glasscontainers as well as those made of metal.

I claim:

1. The process of preventing the adhesion during cooking ofproteinaceous meaty materials to the interior surfaces of a metalcontainer which comprises the step of applying to said interiorsurfaces, prior to cooking the proteinaceous meaty materials in saidcontainer, a coating consisting essentially of a polyhydroxy alcoholpartial ester of a non-hydroxy saturated fatty acid having at least 12carbon atoms.

2. The process of preventing the adhesion during cooking ofproteinaceous meaty materials to the interior surfaces of a metalcontainer which comprises the step of applying to said interiorsurfaces, prior to cooking the proteinaceous meaty materials in saidcontainer, a coating consisting essentially of an esterified fatty acidmaterial selected from the group consisting of polyhydroxy alcoholpartial esters of non-hydroxy saturated and unsaturated fatty acidshaving at 4 least 12 carbon atoms, inner ethers of hexahydroxy alcoholpartial esters of non-hydroxy saturated and unsaturated fatty acidswhich contain at least 12 carbon atoms and mixtures thereof.

3, A container for proteinaceous meaty materials having a metallicinterior surface covered with a coating consisting essentially of anormally solid polyhydroxy alcohol partial ester of a non-hydroxysaturated higher fatty acid containing at least 12 carbon atoms.

4. A container for proteinaceous meaty materials having a metallicinterior surface covered with a coating consisting essentially of 2.normally solid inner ether of a hexahydroxy alcohol partial ester of anon-hydroxy saturated higher fatty acid containing at least 12 carbonatoms.

'5. A container for proteinaceous meaty materials having a metallicinterior surface covered with a coating consisting essentially ofglycerol mono-stearate.

6. A container for proteinaceous meaty materials having a metallicinterior surface covered with a coating consisting essentially ofmannitol mono-stearate.

7. A container for proteinaceous meaty materials having a metallicinterior surface covered with a coating consisting essentially ofsorbitol mono-palmitate.

8. A container for proteinaceous meaty materials having a metallicinterior surface covered with a coating consisting essentially ofmannitan mono-stearate.

9. A container for proteinaceous meaty materials having a metallicinterior surface covered with a coating consisting essentially ofsorbitan mono-stearate.

10. A metal container for proteinaceous meaty materials having itsinterior surface covered with a coating consisting essentially of anesterified fatty acid material selected from the group consisting ofpolyhydroxy alcohol partial esters of non-hydroxy saturated andunsaturated fatty acids having at least 12 carbon atoms, inner ethers ofhexahydroxy alcohol partial esters of non-hydroxy saturated andunsaturated fatty acids which contain at least 12 carbon atoms andmixtures thereof.

11. A metal container for proteinaceous meaty materials having itsinterior surface covered with a coating consisting essentially of apolyhydroxy alcohol partial ester of a non-hydroxy saturated fatty acidhaving at least 12 carbon atoms.

ALBERT c. EDGAR.

References Cited in the file of this patent UNITED STATES PATENTS NumberName 7 Date 2,027,390 Lazier et al Jan. 14, 1935 2,132,701 Richardson eta1. Oct. 3.1, 1938 2,253,655 Shurley Aug. 26, 1941 2,387,626 Ward "Oct.23, 1945 2,398,082 Cavallito Apr. 9, 1946 2,422,486 Johnston June 1'7,194'? OTHER REFERENCES Uses and Applications of Chemicals and RelatedMaterials, 1944, vol. II, by T. 0. Gregory, published byv ReinholdPublishing Corporation, 330 West Forty-second Street, New York, page155, article entitled Glyceryl Monostearate.

Commercial Waxes, 1944, by H. Bennett, pub lished by Chemical PublishingCompany, Inc, Brooklyn, New York, pages and 106, article entitledGlyceryl Monostearate S

1. THE PROCESS OF PREVENTING THE ADHESION DURING COOKING A PROTEINACEOUSMEATY MATERIALS TO THE INTERIOR SURFACES OF A METAL CONTAINER WHICHCOMPRISES THE STEP OF APPLYING TO SAID INTERIOR SURFACES, PRIOR TOCOOKING THE PROTEINACEOUS MEATY MATERIALS IN SAID CONTAINER, A COATINGCONSISTING ESSENTIALLY OF A POLYHDROXY ALCOHOL PARTIAL ESTER OF ANON-HYDROXY SATURATED FATTY ACID HAVING AT LEAST 12 CARBON ATOMS.